Tread for resilient tires.



E. P. EDGECOMBE. Y TREAD PoR RBSILIENT TIRES.

APPLICATION FILED JULYQQ, 1914.

Patented 00u13, v1914.

yicmvnmg n'. nnoncoivrnn, QF GUYAHOGA FALLS, oii'io.

ATREAJJ FOE-BESILIENT TIRES.

to Ithe tire or the roadway.

A still further object Aof .this :invention is to produce of the middle QI" the trend., end fomedji? @gieen-.t @en-1y@ abutment? et Snbetwtially liebt .weie to my @recieve lowes .Set up die t@ propulsion, Shielding,

e'orte.

Sti-.ll @themed further obieet f this in- ;Wll ,in peut he .obvious :ind will in .vennen new be pointed .ont .in .the specificati@ by 0r ,braking Irefeiyenqeto the .aeeoinpanylng drawings, -Wheigeln .like .characters are used to L1ep11e-serit theiteof.

Figline l lis i View eliowing .a plan of o. preferred form .of treed according to my invention. F.ig. A2 .is i view showing' .e section on lines .2&2 Fig. l. illustrating ,the eifeot of a. tread `built in 2.onoiq'lenqe .with ,my invention .when the ltire if rolled Sidewise du@ .to .the meme tum ,0f the vehicle in .rounding nieuwe. 4 is viewillustrating a alight molication of the .prefeigred vfornoof my invention. Fig. 5 ie e, View illustrating@ further modification. .Fine .6 .ond 7 er@ die ammati@ Views illustrating forces .set opg .etween the treed `sui'- ooe oza Atire and `the road snifece, Fig. 8

a .detailed View illustrating `lines of .resistance established by the vpifef'erred forni ofthe treadof .the tire according to my in vention. 'Fign is n.(iietailed View Aillustrating the effect O a projection .when the tire is wider .either braking or propelling etreeses. Fig. 10 is u detailed View illustretiiig the effort ol o. groove in n. tire when like perte thrqughnt .the Several fgulee @Hee-tive onere-i .tion Without inducmg excessive Wear either? V .which (tends to a tire provided with .grooves con: f eltrfueted in the ffice of .the tire 021 web Sid@ I Fig. 3 is a Viewv Specification of Letters Patent.y Wuming wenn' 9, 191g. Asel-iii ivo. 1einen.

'Stanfielly p Patented Got.. 13, 1914.

the ,tipe is under :either propelling or brok" .1.11 Stresses;

V n dealing with the problem of -roacl ve- 12.101? .resilient tiefes .and

.tires V.for ontoinobI that .a groove extending below the general .surface :of .the @ed .meer @ed .firing .sub- 211.131.512 e .Walle is. far moreeffi- AIoo ient end e ive than is a ridge'or iioerticylarlv Pneu# iles .I have found l sentie extending @Weihe general eef @ce Where t @if .the tin@- e pnejectin is Smell t n1e weer .upon lthe thee-id, (9,1' leinzelntiling Hoi'- tion nlieneof, is enceseive, the .result being the@ ,the nrieefiiqri is .Qn destinen@ "if e wheelhe we' wel' .e .110e ,mi of eeft er 100e@ materiel the or@ .eenen hat .n digging eetie .1e 1P .the www, and at the seine time the pigogeqtiqn lprg@Seng-.o only o very sinall ,etijeqtlive Libiitrri enig @orfano against 4the pnroxpiiloiv'ev forties ey ect. The ridge Plzeeente enheeoielly ,t .e .Seme qonditieo .es en isolate@ mieefoe- "In both CaSe-S :the #reoive feines efe @meeneem ie .the .Smell naiss .of eine materiel femme elle 11de@ .or nwiefoil., which' meieriel is there" by-let Ied greatly upon rone sigle .and com?. pressed greatly np'o the other. A emplea, in Fig. 9, o. lportion of jthe pro ectikoii, as @f1-:59 .is under @mme tween portion of .the plnieetinn, .es et Y., 12S undef .heavy compression- Theondtionsexsting neonnetion with n groove ha ving snbgtantially 'ventinol .Wells are `quite dilfer'ent from ,thoee jnstdescribe. In the first place, ,the ,Walls of the Sustained .by the .main .bo @f .the wie md thereby are supported filly, ,either when under Qoinpreejsion or Vunder tension. In the Segond place, the nWeight of the yvehicle upon the tread falce has a ltendency to enrve the edges ,of the ,groove Itoward Ieach yother und'. when this Weight is combinedwith t'aotive effoiit the side of the groove, sustaining the :1t-.tive straetive forces, is Aeulistgintially at .right angles. to the force acting aginst the groove, are is .illuetrated in Fig. 10.

The .tine art ,is 'lledvith various forms of tread snnfeces, including both projections :incl grooves. It is common in the nrt to run a projection or groove entirely' across the normal surface of the tire, that is, aol-oss.

the .medizin line or crown of the tire. In euch cose where the crown vof .the tire is crossed, either by o. ruige or by a groove, the

le the groove are circular continuity of the crown is broken by a short chord. These short chords produce an irregular vibration when the tire is moving over the road surface at a high speed, which vibration tends both to heat and destroy the tire, to cause vibration of the vehicle and to destroy the road surface# y `VVhena vehicle'isrounding acurve there. is always a tendency for the body of the vehicle to continue in a straight line, due' to Newtons law of motion, and this tendency must be vovercome by resistance between' the tire and the road surface, otherwise, the vehicle will skid.` Numerous devices have been designed with the object of meeting this requirement and it is usual to arrange these devices on the middle or tread portion of the tire. It will be seen, however, that when a pneumatic or resilient tire is sustaining side pressure, the tire has a tendency to roll. Under such conditions the crown of the tire ceases to be the active portion. and itis the part to the side of the crown of the tire that is in most intimate contact with the road surface. It has also been common in the art to provide the tread with small cups or pockets which tend to form vacuums when the tire is run over a smooth road surface. The intention being to obtain a grip or hold by the tire upon the road surface. It will be seen that while such devices tend to maintain the tire in close contact with the surface, they also tend to sub- ]ect that portion of the tire to an excessive particularly to and unusual pressure and they furthermore pick up or stir up all the loose particles on the road surface within the zone of action of the tire.

I havev found, and from the foregoing statements it will be noted, that an effective tire can best be constructed wherein the normal tread thereof is smooth and wherein gripping devices are constructed which will present effective abutments at right angles to-any and all forces which may be set up between the tire and `the road surface. Furthermore, that the effective abutment be one wall of a groove, which wall is support- ,ed by the main body of the tire and which groove is so constructed as to prevent the formation of vacuums.

Referring now to the drawings and more Figs. 1 and 2,v it will be noted that my invention includes a vehicle tire 1 havingk the crown thereof, as between the lines A and B, formed with a smooth continuous surface. Continuous grooves 2 and 4 are provided in the tire on each side of the crown portion.. The walls of these continuous grooves 2 and l are preferably perpendicular when in the normal state. The grooves 2 and 4l are congrupus, that is, they are similarwith the exception that the contour of the groove 2 is reversed with reference to the contour of the groove 'l' Fach groovecomprises a plurality of curved parts which include short portions 5 extending adjacent to and substantially parallel with the center portionof 'the crown of the tire. From the portion 'the groove recedes rapidly and extends at substantially right angles to the crown portion of the tire, as at 6. The groove then curves rapidly as at 7 and again becomes substantially parallel to the crown portion, as at 8, and it will be noted that this portion of the groove is farthest away from the center or crown of the tire. The entire contour of the preferred form is but a repetiti'on of the immediate foregoing description, and as will be seen comprises a series of continuous arrhes. Furthermore the side walls of the grooves, constitute abutments which arebelow the wear surface of the tire and are supported by the body of the tire. The facing of the tread portion of the part lying between the continuous grooves 2 and 4: comprises astripof material having substantially the same amount of supporting surface on each side of the crown of the tire and is, continuous so as to present no short chords when the tread is in action.

Figs. 6 and 8 diagrammatically illustrate Vforces that may act on one side of the tire. The arrow D in Fig. 6 indicates the travel of the vehicle. The arrow E indicates the direction of force with reference to the tire if the brakes be set. If the vehicle at the same time be rounding a curve there is a tendency to skid and the force may be a resultant between the braking and the skidding forces. In that case the force would be in the direction of the arrow F. If the vehicle be turned sufficiently in rounding a curve itma b'e suiicient to act on certain tires at righ "angles, as represented by the arrow Gr. The device 10 indicates abutments, such as the side walls of grooves, to

resist the forces indicated by the arrows. Referring now to Fig. 'Z it will be noted that one side ofthe tire, whenunder propelling action, may withstand forces in any direction within.90 degrees, as indicated by arrows H It will also be noted by referring to-the arrows I in this same ligure, that when the vehicle is being propelled through the tire, the tire may receive and sustain any `force through the complementaryv 90 degrees. lt isto be understood that these diagrams represent but one-half of the possible-forces he corresponding half will include the complementary 180 degrees.

Fig. 8 illustrates by the arrow C, that the groove is of such contour as to present surfaces to moet any force within the range of 180 degrees. The oppositely formed groove on the other side of the crown, being identical, presents abutments tof resist forces coming in any direction through the scope of the complementary 1.8() degrees. Therefore it will be seen that by reference to Figs.

ing, a continuous unbroken crown, contina curved line so that the portion of said arranca tl:

2. A resilient tire provided with a tread comprising a continuous unbroken crown, abutments on each side of said crown, saidv abut-ments comprising the side walls of grooves formed i-n the body of said tire, said abutments comprising a continuous Series of flat arches joined at theirfee't and arranged with the middle of thel arch farthest from the center line of the tire?, substantially as described. 6,5

3. A resilient tire including a body ptetion, a tread .formed upon said body portion, said tread including a continuous unbroken crown forming the middle of the tread, a pair of congruous abutments on each side of said crown, said abutments comprising the side walls of grooves formed below the wear surface ofsaid tire, said grooves being continuous and comprising a series of connected arches having the foot of each arch toward the middle of the tire and the bow of the arch beyond the normal tread and parallel' thereto.

. t. A resilient tire comprising in combinal and 8 that a tread formed according to my preferred construction will take up and resist any force between the surface of the tire and the roadway, resulting from tractive or skidding eorts. l

F ig. 3 illustrates the action of a tire under a force in the direction opposite to the ar row-G in Fig. 6. It will be noted that the tire is'rolled so that the central line J is displaced from the vertical, and the side of the tire is now the effective portion to resist forces tending to cause the vehicle to skid. When the tire is in this position substantially the whole side wall of the groove resists the skidding effort, yet at the same time a very effective driving or braking grip is elfected by the portions of the walls of the groove which are at right angles to the drive of the tire.

Fig. Ll is a very slightmodiication of my invention showing the tread constructed with flatter curves to present more abutting surface against skidding forces.

Fig. 5 is a further modification which includes a groove having parts parallel to the crown-portion and also other parts at directly right angles thereto. ln this modiication the arches ll are illustrated as being formed upon segments of circles, andthe feet of the arches l2 comprise short lines substantially parallel to the middle line of the crown of' the tire. Depending from the Centerof the arches are short grooves 14 which extend at right angles to the middle line of the crown of the tire and the edges of these grooves 14 are therefore at right angles to tractive forces parallel to the niiddie line of the tire.

Having thus described my invention what I desire to claim is:

l. A. resilient tire having atread includsaid body portion, said tread having a substantially continuous crown portion including the center line of the tire, continuous abut-ments on each side of said crown portion, said continuous abutments comprising walls of continuous grooves, the walls of each groove being substantially parallel on' a cross section thereof, said abutments comn prising a series of continuous flat arches having the feet of the arches nearest the center of the tire and the bows of the arches farthest from the center of said tire', the feet of the arches of the groove on one side of-VV said crown being arranged Opposite the bows of the arches of the groove on the opposite side of the crown.

5. A. resilient tire including a body portion, a tread formed upon said body portion, said tread including a continuous crown, a continuous abutment formed on said body portion and below the Wear surface thereof, said abutment being curved in .such a manner as to present a surface havinn a tangent at right angles to any tract-ive torce delivered against saidabutment in any direction on one side of the center line of said tire.

EDWARD F. EDGECOMRE. 7itnesses:

Hanny A. EncncoMnl-r, lsMonr A. Pinon.

nous abutments comprising the walls of continuous grooves located on each side of said crown, said abutments being curved and having portions adjacent :said crown and substantially parallel to the center line of' the tire, said abutments then extending rapidly away from the center line of the tire and having a tangent at substantially right y angles thereto, said abutment continuing in abutment farthest from the center line of said tire'has a tangent substantially parallel to the center line of said tire.

tion a. body portion, a tread formed upon 80 

